User name R. Michaels
Log entry time 15:22:27 on July22,2005
Entry number 149033
keyword=cavity signals / gate change
During the controlled access, I looked at the (new) cavity
monitor signals on a scope. The BCM output is flat and near
zero at the few mV level -- this looks ok. But all 4 BPM signals
are oscillating with a frequency of order 1 Mhz and an amplitude
that swings +/- 100 mV (actually a bit asymmetric, and different
for each channel). This does not seem reasonable. I've put in
an inquiry to the electronics experts, Musson et.al.
Another point: I reduced the gate on the ADC 1881M in ROC4
slot 20. It was 110 nsec wide, now it is 50 nsec wide. The
cavity signals are the only thing going to this ADC. This
adjustment will improve the dynamic range of the cavities
in the spectrometer DAQ.